Inlets for aircraft nacelles, wing leading edges, horizontal stabilizers, vertical fins, and other aircraft components may be subject to ice build-up during flight. A heat source may heat the components to prevent the ice build-up or to remove ice after it has built up. The heat source most commonly used today is hot bleed air, but electric resistance heating is under development by several companies. Engine bleed air may supply hot pressurized air to the deicing system and be applied on the backside of surfaces that may form ice in order to heat the surfaces. A pressure regulating valve may be used to regulate the bleed air supply to a constant pressure in the deicing system. However, the temperature of the bleed air varies based on engine operating conditions. For example, during takeoff, the engine is operating at high throttle, and the bleed air is at a relatively high temperature. Even though the pressure of the bleed air supply is regulated, the temperature of the bleed air and the ultimate temperature of the components heated by the bleed air can vary significantly. Designers must take into account the maximum possible temperature a component may reach with the anti-ice system activated, and this can be a very high temperature under certain extreme conditions. The variability of the temperatures created by the anti-icing and deicing system may drive component designs that are overdesigned for most normal operating conditions, that include high-temperature resistant materials that are expensive and heavy, or that pose inconvenient or undesirable flight limitations. Thus, it would be beneficial if the anti-icing or deicing system could control temperatures more precisely.
Composite materials have various advantageous properties over conventional metal materials. In particular, composite materials may be lighter than metals such as aluminum. However, some composite matrix materials do not perform well at high sustained temperatures. If composite materials are used in areas requiring anti-ice or deice capability, the temperature of the bleed air from the anti-icing or deicing system must ensure that certain maximum temperature allowables are not exceeded. Better thermal management of anti-icing and de-icing systems would facilitate further composite penetration into aircraft structures.